Figure 3

Gene expression profiles of C. stoebe geo-cytotypes. For each sample, total RNA (ng/ul) was estimated using the appropriate standard curve for each gene of interest and normalized using the geometric mean of the standards actin, cytochrome c oxidase, and ubiquitin as suggested in Vandersompele et al. 2002 [61]. Significant differences in gene expression (log cDNA) were determined for geo-cytotypes of interest (EU 2× versus EU 4× and EU 4× versus US 4×) using pair-wise comparisons of LSmeans. Bars represent back-transformed LSmeans and standard errors. Fisher's LSD was used for pair-wise mean comparisons, and values are reported in Table 1. Different letters above the columns indicate significant differences (P < 0.05) between pairs of geo-cytotypes. Legend; 2× EU, native Eurasian diploid populations; 4× EU, native Eurasian tetraploid populations; 4× US, invasive North American tetraploids. Panel A: Genes involved in secondary metabolism; PAL (Phenylalanine ammonia lyase) 1, 2a, 2b. Panel B: Genes involved in defense response; Chit (chitinase) and Gluc (glucanase); Panel C: Gene involved in transposition; TE (transposable element); Panel D: Gene involved in DNA repair and recombination, RAD.